package servlet;

import java.io.IOException;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.lang.*;
import bean.ConnectMySql;
import java.io.PrintWriter;

@WebServlet("/addCart")
public class addCart extends HttpServlet {
	private static final long serialVersionUID = 1L;
       
    /**
     * @see HttpServlet#HttpServlet()
     */
    public addCart() {
        super();
        // TODO Auto-generated constructor stub
    }

	/**
	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		request.setCharacterEncoding("UTF-8");
		String dishId=request.getParameter("dishId");
		try {
			  HttpSession session=request.getSession();
			  String userId=(String)session.getAttribute("xxx");
			  PreparedStatement st1=null;
			  ResultSet rs = null;
		      Connection con1=ConnectMySql.getConnection();
		      st1=con1.prepareStatement("select * from cart where dishId=? and userId=?");
		      st1.setInt(1,Integer.valueOf(dishId));
		      st1.setInt(2,Integer.valueOf(userId));
		      rs=st1.executeQuery();
		      if(rs.next()){
		    	  st1=con1.prepareStatement("update cart set quantity=? where cartId=?");
		    	  int quantity=rs.getInt(4);
		    	  quantity++;
		    	  st1.setInt(1,quantity);
		    	  st1.setInt(2,rs.getInt(1));
		    	  st1.executeUpdate();
		      }else {
		    	  st1=con1.prepareStatement("insert into cart values(null,?,?,1)");
		    	  st1.setInt(1,Integer.valueOf(userId));
		    	  st1.setInt(2,Integer.valueOf(dishId));
		    	  st1.executeUpdate();
		      }
	          ConnectMySql.closeStatement(st1);
	  		  ConnectMySql.closeConnection(con1);
			}catch(SQLException e) {
				e.printStackTrace();
		}
		response.sendRedirect("shop.jsp");
	}

	/**
	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		doGet(request, response);
	}

}
